Pablo Neira Ayuso <pa...@netfilter.org> writes:
> On Wed, May 11, 2016 at 05:41:13PM +0200, Florian Westphal wrote:
>> diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
>> index 5baa8e2..9722819 100644
>> --- a/net/netfilter/nf_queue.c
>> +++ b/net/netfilter/nf_queue.c
>> @@ -102,6 +102,13 @@ void nf_queue_nf_hook_drop(struct net *net, struct
>> nf_hook_ops *ops)
>> {
>> const struct nf_queue_handler *qh;
>>
>> + /* netns wasn't initialized, error unwind in progress.
>> + * Its possible that the nfq netns init function was not even
>> + * called, in which case nfq pernetns data is in undefined state.
>> + */
>> + if (!net->list.next)
>> + return;
>
> Thanks Florian.
>
> Question for the netns folks: Is this a stable assumption? My only
> concern with this is that it relies on internal the netns
> representation, so I'd like to make sure this thing doesn't break
> again.
>
> Let me know, thanks.
Ugh. I got distracted before I finished replying.
I don't think the analysis is correct.
The unwind and the netns exit path should maintain the same constraints.
If they don't there is a bug, perhaps in initialization ordering.
Code should be able to count on net_generic() from the beginning of the
corresponding .init to the end of the corresponding .fini
Something like that is not happening and if we can I would like to track
down why.
Otherwise we need code like the above all over the place.
Eric
